High speed machining of metal parts is a newly emerging technology which allows accurate and high speed manufacture of milled and drilled parts. This technology can be used to eliminate riveted sheet metal assemblies, for example. In high speed machining, the machine spindle and cutter are rotated at speeds of twenty five thousand RPM, or greater. To achieve high precision, the cutters are mounted in the machine spindle by means of short taper holders or holders.
One way of mounting a cutter in the holder is to heat the holder to temperatures of about 750.degree. F. so as to expand the inside diameter of the holder. The cutter shank is then inserted into the holder and the latter is cooled so as to shrink fit the holder onto the cutter shank. The holder and cutter are then mounted on the machine tool spindle. This procedure is not desirable due to the fact that it requires a very precise cutter shank and holder axis alignment at the time of cutter-to-holder insertion; and, in addition, tools which are mounted in this fashion do not have a very extensive useful life due to the fact that the tool holder is heated and then cooled which causes deterioration of the tool holder material.
Another way to connect the cutter to the spindle is the use of a spindle that has a split holder inside of it. The cutter shank is inserted into the holder and a collar on the spindle is twisted so as to radially squeeze the holder onto the cutter shank.
A third way to mount the cutter in the spindle includes a set screw which is threaded into the side of the spindle and which is tightened down onto the cutter shank after the latter has been inserted into the spindle.
In each of the aforesaid mounted schemes, there is no way to adjust the cutter axis so as to ensure that the cutter and the spindle are aligned after the cutter has been mounted in the spindle. Cutter-spindle misalignment results in erratically machined parts, surface finish imperfections, and tool imbalance. Users of high speed machining have no solution to the problem of cutter-spindle misalignment, and therefore it is presently merely tolerated. It would be highly desirable to provide a solution to the aforesaid cutter-spindle alignment, or misalignment if you will, problem.